This is a continuation of the Macular Photocoagulation Study, of which there were eight and now 12 centers in the United States. The purpose of the trial is to determine the effect of argon laser photocoagulation in patients with idiopathic choroidal neovascularization, senile macular degeneration and histoplasmic subretinal neovascularization. The patients are being recruited into the study (3 per month) in order to determine whether "treatment" or "no treatment" is the superior method. Our clinic is complying with the overall Coordinating Center under the direction of Dr. Stuart Fine of Johns Hopkins University.